Polarized relay.



NO MODEIW PATENTED MAR. 8,-1904. M. 0. RORTY.

POLARIZED RELAY.

APPLIOATION FILED JUNE 1a. 1003.

THE Norms prrzns co, ruoTaumo" wnummom o. c

UNITED STATES Patented March 8, 1904.

PATENT OFFICE.

MALCOLM O. RORTY, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO AMERICANTELEPHONE AND TELEGRAPH COMPANY, A COR- PORATION OF NEW YORK.

POLARIZED RELAY.

SPECIFICATION forming part of Letters Patent No. 753,918, dated March 8,1904.

Application filed June 18, 1903.

the following is a specification.

The present inventionis an improvement in relays, and particularly inthat class of polarized relays which are employed in association withtelephoneswitchboards to control the display of signals, to connect anddisconnect the original circuit-terminals, and generally to afford aconvenient means for the automatic eifectuation of simple circuitchanges.

The object of the invention is to provide an exceedingly compact relaydevice which shall be simple in construction and certain and eflicientin operation.

To this end the operating-armature is poised or fulcrumed upon one poleof a permanent magnet and is suspended and arranged to swing oroscillate in an armature-space between confronting poles of anelectromagnet having an exciting-coil wound over or surrounding one onlyof its limbs and having its heel secured to the other pole of saidpermanent magnet. The armature-pole of the permanent magnet is formed atits end into a bevel or knife edge on which the armature is adapted torock, the

' by reference to the drawings which accompany this specification,wherein- Figure 1 represents a side elevation of the relay constitutingthe invention in a preferred form. Figs. 2, 3, and A are respectively aplan view and rear and front elevational views thereof. Fig. 5 is a sideelevation of a relay Serial No. 162,109. (No model.)

containing the invention, but with amodified armature-lever attachmentand modified means for securing the armature to the permanentmagnet-pole; and Fig. 6 is a front view of the armature associated withthe relay so modified. Fig. 7 is a diagram of signal-circuits involvingthe employment of the said relay and illustrating the operation thereof.K

A is the electromagnet, with confronting poles p and 19 M is therectangular permanent polarizingmagnet, arranged with its straight stemm parallel to the limbs of the electromagnet and its poles w. and 0 insuch relation to the electromagnet that bothpoles of said electromagnetare magnetized by one of them, 0, while the other, 71, is held oppositethe armature-space between the confronting poles p12 of saidelectromagnet.

H is the armature, fulcrumed on the polar end 12. of the permanentmagnet, which may be formed with a bevel edge, as in Fig. 1, or aknife-edge, as in Fig. 5, for this purpose, being held in place by asuitable screw or screws and suspended from said pole within thearmature-space z. The said armature H is provided with a continuationangle-piece 7b, extending backward over the stem of the permanentmagnet, the armature and its continuation conjointly constituting alever whose fulcrum is the beveled pole n of the permanent magnet.

It will be seen that the main function of the permanent magnet M is toimpart an initial magnetization of the same sign to the two confrontingpoles of the electromagnet A and of opposite sign to the armature H,which hangs between them. The said armature being thus between two likepoles is normally subject to like attraction by both, but is held towardthe pole p by the pressure of the spring f on the angle-piece it; butwhen the pole p is strengthened and the pole p neutralized orcorrespondingly weakened, which condition is brought about bytransmitting through the coil S an electric current of appropriatedirection, the armature is attracted by and moves toward thestrengthened pole p and is thus enabled to operate the circuit-changingsprings 8 8 One or more banks of contact-springs s 8 forming terminalsof circuit-conductors 2 3 4, are conveniently mounted Within range ofthe free end of the armature continuation h and are adapted to beengaged thereby, so that their normal contact relations may be alteredand the several possible arrangements of contact established anddisestablished by the movements thereof as the armature is attractedtoward one or the other of the electromagnet-poles.

Referring for the present more especially to Figs. 1, 2, 3, and 4c, theelectromagnet A is composed of an iron core having two limbs orconstituent cores. The constituent core a is a straight bar terminatingforwardly in the pole or polar end 2), and the other or complementaryconstituent core, 7), is a bar formed with its middle portion or stemstraight and both ends turned at an angle in like direction to overlapthe ends of the straight core a. The angular end of the complementarycore 6, which overlaps the rear or heel end of the straight core a, issecured directly thereto by the screw K, while the stem part, extendedforward over and closely adjacent to the exterior of the coil S, bringsthe other end to a position beyond the pole p of the straightconstituent core, where its forward angular end is enabled to confrontsaid pole at a short distance therefrom, forming the pole p of theelectromagnet and producing the armaturespace 2 between the poles.

The electromagnet A has, preferably for economy of space and on thescore of compactness, a single exciting helix or coil, and the said coilS is wound over or surrounds the straight core a.

The terminal wires of the electromagnetic spool emerge through holes 6in the rear head thereof and are provided with rigid attachments 0 forconnection with the circuit-wires.

The permanent magnet is a rectangular bar of permanently-magnetizedsteel bent at the point y to a right angle, with a long arm at and ashort arm m The short arm m is rigidly attached at its pole 0 to theheel of the electromagnet, whose two limbs thus become continuations ofone of the permanent magnet-poles, and is secured thereto in anypreferred manner, as by screws. As shown in Figs. 1 and 3, the screw Kmay be utilized not merely to unite the two limbs of the electromagnet,but also to unite both to the said short arm m of the permanent magnet.The longer arm m of the permanent magnet extends forward over the coilor spool S of the electromagnet toward the poles of said electromagnet,its pole 12 being arranged to overhang the armature-space .2 thereof andbeveled to form a rocking edge or fulcrum, whereon the armature H may bepoised. The said longer arm m occupies the same position vertical to theperiphery of the exciting-coil on one side thereof that the straightmiddle portion or stem of the complementary core I) occupies on theother side, and the said coil may therefore be described as surroundingor en circling the straight core a of the electromagnet A and fittedbetween the stem of the complementary core 6 of said magnet and thelonger arm on of the permanent magnet M in close contiguity to both,thus forming an exceedingly compact electromagnetic organization ormechanism.

The armature H is poised on the bevel edge of the pole 07, of thepermanent magnet and is suspended, as shown, in the armature-spacebetween the poles p of the electromagnet. It may be provided with frontand rear stoppins it" h to prevent it from striking the poles p and p orfrom approaching them too closely. To secure the said armature fromdisplacement without interfering with its freedom of motion oroscillation, screws 2f 25 pass through holes in the angular extension 71and engage threaded holes in the magnet-pole n, the said holes in thearmature extension being made large enough for the loose and freeadmission of said screws and the heads of said screws when in placebeing out of contact with the surface of said extension and heldsufiiciently far away therefrom to insure the free play thereof.

Two banks of contact-springs s and s" are shown as being mounted withinrange of the armature continuation or lever attachment /1/, which in thepresent instance consists of a plate integral with and similar in widthand thickness to that which forms the armature itself, being, however,turned back substantially at a right angle therewith. Each bankcomprises three springs connected with circuit-conductors 2, 3, and 4,respectively. The several springs are insulated from one another andfrom the magnet-stem m by interposed non-conducting washers w, and ineach case the middle spring of the three extends sufliciently far towardthe armature end of the relay as to rest immediately above the end ofthe armature continuation lb. The two lower springs of each bank areshown as being in normal contact with one another; but by raising thefree end of the middle spring such normal contact can be broken and analternative one formed between the middle and upper springs, so that acircuit previously established between the conductors 3 and 4: isdisestablished and a new one between conductors 3 and 2 is completed. Anon-conducting guide-stud may be attached to the back of thepermanent-magnet arm m, and a pin extending therefrom projects throughsuitably wide holes in the two lower springs of the set and impingesagainst the under side of the uppermost spring to serve as a normal sup-Similar studs f may in like port therefor.

manner be attached to the upper surface of the end of the armature-leverextension directly below the end of the middle springs, and these whenthe armature is attracted and rocks on its pivot are pressed againstsaid spring to bring about its change of position. Obviously the springsexercise reverse pressure on said armature extension 72, and are thusenabled to serve also as a retracting agency for the armature.

The form of relay particularly shown in Figs. and 6 is not in anymaterial sense different from that already described. It is,

however, modified in the following respects:

a plate of width equal to that of the armature itself and made in onepiece therewith consists of two pins 71, of brass or similar suitablemetal, riveted or otherwise attached to the armature at the points i andextending, respectively, below the two banks of contactsprings s 3 Underthese conditions the armature H does not obtain any support from theback of the stem m of the permanent magnet and is held in place upon theknife-edge by a screw is, which enters a threaded hole bored into theapex of said knife-edge, elasticity being imparted to said knife-edge bya helical spring a, surrounding said screw.

The diagram, Fig. 7, illustrates one application of the relay of thisinvention. Two such relays R and R are connected in different branchcircuits E E both connected with a main circuit D, associated with asource of current V and two keys or push-buttons P P,

adapted to connect said source with the saidmain circuit D. The key Pwhen operated connects the plus-pole of the said source V with conductor6 and the minus-pole thereof with conductor 5 of the circuit, and theoperation of the key P establishes the connection in reverse order. Thedirection of the current in the circuit D and its branches E E thusdepends upon which key is depressed. In one case, that wherein key P isoperated, 6 and its branches 7 and 17 are the outgoing conductors and 5and its branches 8 and 18 are the return conductors. In the other casewhen the key P is the one operated 5 and its branches 8 and 18 are theoutgoing conductors and 6, 7, and 17 the returns. The relays R R areoppositely polarized or oppositely connected, which of course amounts tothe same thing, and actuate separate sets of contactsprings s, whichcontrol separate local circuits Q and Q containing, respectively,signallamps Q and Q2. Thus the pressure of the key P will result in theoperation of one only of the relayssayR-and the consequent display ofsignal (1, while the operation of the key P will in like manner bringabout the operation of the relay R alone and the display of signal 9Having fully described the invention, the features thereof claimed asnew are 1. The hereinbefore-described relay, com prising anelectromagnet with confronting poles; a permanent polarizing-magnetmounted parallel to the limbs of said electromagnet and having its polesin juxtaposition to the heel and poles respectively thereof;contactsprings mounted upon said permanent magnet; an armature suspendedbetween the confronting poles of said electromagnet and poised orfulcrumed on the permanent-magnet pole nearest thereto, and-having anattachment or continuation extending backward over said permanentmagnet; said armature and attachment constituting a lever actuated bysaid electromagnet and adapted to engage said contact-springs for thecontrol of their reciprocal relation.

2. In arelay, the combination of an electromagnet with confrontingpoles; a permanent polarizing-magnet mounted parallel to the limbs ofsaid electromagnet and having one pole attached to the heel and theother extended forward into contiguity to the poles thereof;contact-springs of a controlled circuit mounted upon said permanentmagnet; an armature poised or fulcrumed upon the said forwardly-extendedpermanent-magnet pole to be polarized thereby, and suspended therefrombetween the poles of said electromagnet; and an attachment orcontinuation of said armature extending backward therefrom over saidpermanent magnet beneath said contactsprings and constituting conjointlywith said armature a lever actuated in both directions by the poles ofsaid electromagnet, and adapted thereupon to establish or disestablishthe contacts of said springs; substantially as set forth.

3. In a polarized relay, the combination of an electromagnet with onelimb only surrounded by an exciting-coil and the other extended forwardadjacent to said coil, and having the pole of the latter limb turned atan angle to confront that of the former with an armaturespace between; arectangular permanent polarizing-magnet mounted parallel to saidelectromagnet having one pole secured to the heel and theother extendedforward into juxtaposition to the poles thereof; contact-springs of acontrolled local circuit mounted upon and supported by said permanentmagnet; and a rectangular lever poised or fulcrumed upon the forwardpole of said permanent magnet and having one end suspended from saidpermanent magnet in the said space between the poles of saidelectromagnet to form the armature thereof, and the other extendedrearioo wardly over said permanent magnet, and beneath and in engagementwith the said contact-springs; substantially as and for the purposesdescribed.

4:. The combination in a polarized relay, of a straight iron core; acomplementary iron core with a straight stem and both ends turned at aright angle to overlap the ends of said straight core, one being securedto the heel end, and the other constituting a pole arranged to confrontthe pole end thereof, with an intervening armature-space; a rectangularpermanent bar-magnet having one pole secured to the heel of said cores,and the other extended forward to a point opposite the armature-spacethereof and formed at its end into a bevel or knife edge; the stems ofsaid bar-magnet and cores being all parallel to one another; anexciting-coil surrounding the said straight core, and fitted between thesaid permanent bar-magnet and the stem of said complementary core; anarmature suspended in the space between the poles of said cores, andpoised or fulcrumed to swing on the knifeedge pole of said permanentmagnet; and electrical contacts controlled by said armature;substantially as specified.

5. The combination in a polarized relay, of an electrom agnet comprisinga single excitingcoil, and an iron core hax ing two limbs one surroundedby said coil and the other extended forward adjacent to the exteriorthereof and having its polar end prolonged beyond the pole of theinterior limb and turned at an angle to overlap and face the same at anappropriate distance to form an armature-space between said poles; arectangular permanent polarizing-magnet having one pole secured to theheel and the other extending to the said armature-space of saidelectromagnet, and terminating in a beveled or knife edge; and anarmature secured to said permanent magnet, balanced on the knife-edgepole thereof, and suspended in the armature-space between the poles ofsaid electromagnet; substantially as set forth.

In testimony whereof I have signed my name to this specification, in thepresence of two subscribing witnesses, this 15th day of June, 1903.

MALCOLM C. RORTY.

Witnesses:

Geo. VILLIs PIERCE, Josnrn A. GATELY.

